Dermatobia Research Articles

Ultrasound features of cutaneous myiasis: a rare case in a child.

Cutaneous myiasis is an infestation of the skin with larvae of some dipteran species. Among humans, Dermatobia hominis is the most frequently encountered dipteran responsible for cutaneous myiasis. This insect is endemic to tropical and subtropical regions, consequently, individuals travelling from non-endemic areas are most susceptible to infection due to a lack of prior exposure. Three clinical variants of myiasis are distinguished: furuncular, migratory, and wound myiasis. Furuncular myiasis represents the most common form among travelers, yet it is a rare cause of pediatric skin manifestations in developed countries. Limited awareness of this condition in non-endemic regions contributes to diagnostic challenges. In this scenario, ultrasound is useful in the diagnostic workup, enabling the identification of the viable larva.

An update review on monoterpene indole alkaloids and biological activities of Tabernaemontana species occurring in Brazil

Ethnopharmacological relevanceThe Tabernaemontana genus belongs to the Apocynaceae family of which 30 species are found in Brazil. Some Tabernaemontana species are used by Brazilian indigenous people and other communities, or are listed in the Yanomami Pharmacopeia. Ethnopharmacological data include use(s) for muscle problems, depressed sternum, back pain, abscess, indigestion, eye irritation, earache, itching, vaginal discharge, as an aid for older people who are slow and forgetful, mosquito and snake bites, infection by the human botfly larvae, calmative, and fever. Obviously, many of these uses are attributed to the alkaloids found in Tabernaemontana species. Aim of the reviewThe aim is to gather information on Tabernaemontana species occurring in Brazil, as sources of monoterpene indole alkaloids (MIAs). In addition, we aim to collect reported experimental demonstrations of their biological activity, which may provide the foundation for further studies, including phytochemistry, the development of medicinal agents, and validation of phytopreparations. Material and methodsThe Brazilian Flora 2020 database was used as source for Tabernamontana species occurring in Brazil. The literature review on these species was collected from Web of Science, Scopus, PubMed, and Scifinder. The keywords included names and synonyms of Tabernaemontana species found in Brazil, which were validated by the Word Flora Online Plant List. ResultsA literature survey covering the time frame from 1960 until June 2023 resulted in 121 MIAs, including 48 not yet reported in the last review published in 2016. Some alkaloid extracts, fractions, and isolated alkaloids present evidenced biological activity, such as anticancer, anti-inflammatory, antinociceptive, antimicrobial, antiparasitic, antiviral, and against snake venoms, among others. Notably, ethnopharmacological based information has been the basis of some reports on Tabernaemontana species. ConclusionsOur literature survey shows that Tabernaemontana species present bioactive MIAs, such as voacamine and affinisine, demonstrating significant cytotoxicity activity against several tumoral cell lines. Those compounds can be considered promising candidates in the search for new anticancer drugs. However, the Amazonian plant biome is increasingly damaged, which may lead to the extinction of biological diversity. This threat may also affect Tabernaemontana species, which have scarcely been investigated regarding the potential of their phytochemicals for the development of new drugs.

Effectiveness of lotilaner on furuncular myiasis in dogs naturally infested with Dermatobia hominis (Diptera: Cuterebridae).

An evaluation was made of the larvicidal efficacy of lotilaner (Credeli®) in the treatment of dogs naturally infested with Dermatobia hominis larvae. A total of 12 dogs presenting at least three live D. hominis larvae were medicated. The animals were medicated orally with a single dose of no less than 20 mg/kg lotilaner. After drug administration, the animals remained at their homes, and observations were made to verify the larvicidal effect 6 hours after treatment. Live larvae were considered any parasite that exhibited motility after removal. For each animal was using the formula: 100 x [(total of live larvae before treatment - total live larvae after treatment) /total of live larvae before treatment] as criteria for evaluating lotilaner efficacy. A total of 98 larvae were counted in 12 dogs, with an average of 8.1 larvae per animal. The effectiveness of lotilaner was 80.6%. Nineteen larvae were found alive, albeit presenting hypomobility and lethargic behavior. However, note that the evaluation was performed just six hours after administration of the drug. Lotilaner administered orally in a single dose of 20 mg/kg showed 80.6% efficacy six hours after treating dogs naturally infested with D. hominis.

Furuncular myiasis caused by Dermatobia hominis: entodermoscopic findings.

A 27-year-old male traveller returning from the Amazon forest came to our dermatology consultation with a furuncle-like nodule in the temporal region. During examination we observed an erythematous nodule with a central opening. We describe the entodermoscopic characteristics of Dermatobia hominis.

Ophthalmomyiasis Externa and Importance of Risk Factors, Clinical Manifestations, and Diagnosis: Review of the Medical Literature.

This review aims to describe and compare the risk factors, clinical course, diagnosis, and parasitologic features of external ophthalmomyiasis. We also discuss the different preventive measures and the effect of global warming in a large case series reported from January 2000 to December 2022. We perform a literature review of reported cases of external ophthalmomyiasis to determine the clinical characteristics, therapeutic management, and information on the organisms that most commonly cause external ophthalmomyiasis. A total of 312 cases of external ophthalmomyiasis were recorded. The most common causative organism was Oestrus ovis (Linnaeus) (Diptera: Oestridae), accounting for 72.1% of cases, followed by Dermatobia hominis (Linnaeus Jr. in Pallas, 1781) (Diptera: Oestridae) at 5.4%, Lucilia sericata (Meigen) (Diptera: Calliphoridae) at 0.96%, and Chrysomyia bezziana (Villeneuve) (Diptera: Calliphoridae) at 0.96%. Before experiencing symptoms, 43.6% of cases reported having direct contact with flies or being hit in the eye, 33% reported no associated risk factors, 9.3% reported living with sheep and goats, and 7.7% reported a history of foreign objects entering the eye. The most common symptoms for those affected by O. ovis were sudden onset, including a foreign body sensation and movement, redness, tearing, itching, swelling, irritation, photophobia, burning, and ocular secretion. In cases caused by D. hominis, symptoms included eyelid edema, pain, redness, itching, movement within the lesion, ocular irritation, and discharge. Regarding occupational or recreational activity, agriculture, and livestock had the highest incidence, followed by trades and technical activities, being a student, and having traveled to an endemic region for work or recreation. Patients with red eyes may suffer from external ophthalmomyiasis, which requires a thorough examination to diagnose and treat it early. Moreover, as the temperature increases due to climate change, it is essential to consider how this will affect the spread of different pathogens.

Cutaneous Furuncular Myiasis in a Rural Kenyan Hospital: A Case Report

Myiasis is a neglected tropical disease caused by infestation by the larval stages (maggots) of many species of flies, which occur worldwide but are more prevalent in the tropical and subtropical regions. The two main types of flies causing human myiasis are Dermatobia hominis (bot fly) and Cordylobia anthropophaga (tumbu fly). Cases of human myiasis in Kenya are not well documented, but some epidemiological studies show the tumbu fly to be the most prevalent. Transmission and infestation occur in cases of poor personal and environmental hygiene, especially in spaces shared with wild and domestic animals. Cutaneous myiasis, presenting as a furuncular, wound, and migratory disease, is the most common clinical phenotype that may be associated with secondary pyogenic infection and cellulitis, especially when not treated promptly. In this study, we present a case of cutaneous furuncular myiasis in a patient from rural Kenya. We share our experience managing the patient and also provide a literature review on the clinical case management of myiasis, with a call for more epidemiological and clinical work to be done to better understand this neglected disease.

Twinkle Artifact Observed During POCUS of a Human Myiasis Caused by the Dermatobia hominis Botfly

An 81-year-old man presented to urgent care for assessment of an area of erythema and tenderness on his right thigh after recent travel to Belize. Point of care ultrasound (POCUS) revealed a hyperechoic structure with acoustic shadowing in the subcutaneous tissue. Colour Doppler assessment of the structure produced a twinkle artifact. The structure was removed and pathology identified the object as a Dermatobia hominis larva (human botfly). The use of POCUS helped identify and localize the subcutaneous foreign body. The use of colour Doppler produced the twinkle artifact, which has not been previously reported as a finding produced during ultrasonographic assessment of botfly larvae.

First report of the efficacy of a fluralaner-based pour-on product (Exzolt® 5%) against ectoparasites infesting cattle in Brazil

BackgroundThis study describes the effectiveness of a novel active pharmaceutical ingredient, fluralaner (isoxazoline class), against important ectoparasites infesting cattle in Brazil.MethodsA total of 13 studies involving a 5% fluralaner-based pour-on formulation (Exzolt 5%; further referred to as Exzolt) were conducted. Specifically, the effectiveness of this formulation was studied against Rhipicephalus microplus (6 studies), Cochliomyia hominivorax larvae (4 studies), Dermatobia hominis larvae (1 study) and Haematobia irritans flies (2 studies).ResultsThe therapeutic efficacy of Exzolt was found to exceed 98% at 4 days post treatment (DPT), while persistent efficacy (> 90% efficacy) against repeated infestations of R. microplus was observed for up to 79 DPT. In field studies, ≥ 98% therapeutic efficacy was demonstrated at all study sites by 7 DPT, and a persistent efficacy (> 90% efficacy) was observed for 42, 49 or 56 DPT. Exzolt prevented C. hominivorax eggs from developing to the larval stage, thus mitigating the development of myiasis in cattle naturally and artificially infested with this screworm. The efficacy of Exzolt against D. hominis larvae was 98% at 3 DPT, while persistent efficacy (> 90% effectiveness) was found to last for up to 70 DPT. Against H. irritans, Exzolt showed therapeutic efficacy (≥ 90%) within the first day of treatment at both study sites, while persistent efficacy (≥ 90%) was observed for 7 DPT at one site and for 21 DPT at the other site.ConclusionsOverall, the results from these studies confirm that Exzolt is therapeutically efficacious against the most important ectoparasites infesting cattle in Brazil. The novel active pharmaceutical ingredient, fluralaner, provides a new treatment option for farmers to control cattle ectoparasites, especially where there is resistance to other chemical classes. In addition, an effective control of ectoparasites will improve overall cattle health and well-being as well as production.Graphical

Cuterebra baeri Infecting Grey-Legged Night Monkeys (Aotus griseimembra) and Red Howler Monkeys (Alouatta seniculus) in Colombia.

Myiases are parasitic infections caused by the larval stages of some fly species. In American nonhuman primates (NHP), three bot fly species causing cutaneous myiasis have been reported: Cuterebra baeri, Cochliomyia hominivorax, and Dermatobia hominis. Studies on myiasis in NHP are scarce and mainly based on morphologic identification of larvae, while molecular approaches have been barely used. This study aimed to molecularly identify bot flies parasitizing two NHP species living sympatrically in central Colombia. Bot fly larvae were collected from two grey-legged night monkeys (Aotus griseimembra) and from a howler monkey (Alouatta seniculus). Larvae were measured and photographed for morphologic evaluation; subsequent molecular characterizations of a partial region of the cytochrome c oxidase subunit 1 mitochondrial gene were performed. Sequence analysis allowed the identification of all specimens as Cuterebra baeri, enabling confirmation of this species parasitizing Alouatta seniculus and Aotus griseimembra in Colombia.

Controle da larva de Dermatobia hominis com extração manual é efetivo e não causa abscesso

ABSTRACT: In order to study alternative ways of control of Dermatobia hominis fly larvae, three processes were tested: T1, cypermethrin 5% + chlorpyrifos 7% + citronellal 0.5% (Pour on); T2, trichlorfon powder dissolved at 2% in burnt oil passed on the nodules; T3, manual larva extraction. The study was conducted at Instituto de Zootecnia in Nova Odessa, São Paulo State, Brazil. In a dairy herd of 176 animals, 29 with at least one larvae were found, distributed in the three treatments. Each treatment’s efficacy percentage was based on the number of live botflies present after 14 days. The animals were observed on days +4, +7, +14 and +21, and new botflies and abscesses were annotated. All treatments presented high effectiveness (above 98%). New botflies were already seen in the first week after applying the three treatments, and on day 21, two abscesses in each chemical treatment were observed. Larva extraction was 100% effective, with no originating abscesses, and should be encouraged in small and medium-sized properties and those with resistant botflies to chemical products.

EXTERNAL OPHTHALMOMYIASIS

Ophthalmomyiasis is a zoonotic disease most often caused by the larvae of oestrus ovis (sheep fly). Thefemale O. ovis retains her eggs within her body until they hatch, and then typically deposits her larvae into thenostrils of sheep and goats. Larvae of Oestrus ovis are obligate parasites of the nasal and sinus cavities of sheep andgoats, so this parasite is widespread in countries where the climate is hot and dry and sheep and goats are numerous.Therefore, it usually occurs in shepherds and farmers in rural areas, but it has also been observed in urban areas andin close contact with animals. In addition to oestrus ovis, there are other species that can cause this disease - thehuman bot fly (Dermatobia Hominis), midge (Fannia), house fly (Musca domestica) and cattle (Hypoderma).Ophthalmomyiasis is classified as external if the larvae are present on the lids or conjunctiva, and internal whenthere is intraocular penetration of the larvae, which affects the retina and if left untreated can lead to blindness.Intraocular penetration of larvae, or ophthalmomyiasis interna, is less common worldwide than ophthalmomyiasisexterna. It is known to occur at various anatomical sites including skin, eye, nose, paranasal sinuses, throat,intestine, and urogenital tract Conjunctival myiasis is the most common form of ophthalmomyiasis, and it is arelatively mild, self-limited, and benign disease.An ocular involvement occurs in about < 5% of all the cases ofhuman myiasis.Risk factors include eye infections, eye sores, advanced age, frailty, poor general health. Symptoms are described asforeign body sensation with lacrimation, conjunctival hyperemia and pruritus followed by eye pain. These initialsigns and symptoms of ophthalmomyiasis externa may mimic conjunctivitis. All movements of the larva are clearlyvisible from the side, which greatly facilitates its detection and diagnosis. Ophthalmomyiasis can be treatedefficiently ,if identified in time The treatment is based on the manual extraction of all larvae under local anesthesia,followed by washing or rinsing the eyes and local treatment. Prevention has always been better than cure. Goodpersonal hygiene can avert significant complications caused by ophthalmomyiasis Cases of ophthalmomiasis havebeen reported in countries around the world including Afghanistan, Pakistan, Kuwait, Iraq, Libya, Tunisia, Russia,India, USA, Canada, Croatia Slovenia. In the Republic of North Macedonia in 2022, 4 cases of ophthalmomiasiswere diagnosed and treated at the Shtip Clinical Hospital. It is characteristic that all the patients are men who areengaged in animal husbandry and agriculture and they are from a rural environment. Myiasis should be consideredas an occupational disease in farmers and shepherds.

Furuncular cutaneous myiasis in Saudi Arabia

Myiasis is the infestation of a living vertebrate by a fly's larva, completing its obligate life cycle. Exposed skin remains the most affected site. The botfly, Dermatobia hominis , is the most common cause of cutaneous furuncular myiasis in tropical areas. Few cases have been reported in Saudi Arabia, mainly in the Southern region. A one-year-old medically free child presented to our pediatric surgery clinic with a painful, itchy discharging nodule on the inner aspect of his right forearm for one-week. The patient's mother and sibling had a similar former presentation after visiting Taif city. We dilated the central punctum and extracted the larva fully intact. The larva was identified morphologically as Dermatobia hominis by a parasitologist. The lesion was left to heal secondarily, which resulted in an acceptable cosmetic result and minimal scarring. Raising this clinical entity's awareness between pediatric surgeons will set aside misdiagnosis, delayed management, and possible complications. A high level of suspicion and careful history taking are required to recognize myiasis, particularly in patients with a recent history of global traveling or those with close contact with cattle.

Prevalence, Etiology, and Risk Factors Associated with Occurrence of Canine Cutaneous Myiasis in Kitui County, Kenya.

Myiasis is the infestation of living tissues of animals with dipterous larvae. In Africa, Cordylobia species (C. anthropophaga, C. rodhaini, and C. ruandae) and Dermatobia hominis are reported as the principal cause of nonmigratory cutaneous myiasis of domestic animals. None of these have been reported in dogs in Kenya. A cross-sectional study was conducted in eight subcounties of Kitui County, Kenya, from March to August 2021 to estimate the prevalence, risk factors, and etiological agents associated with canine cutaneous myiasis (CCM). A questionnaire was administered to dog owners to collect information on CCM risk factors. A total of 400 dogs were physically examined and larvae collected from myiasis skin lesions and preserved in 70% ethanol, taken to the laboratory, processed and identified using parasitological morphological features. Live larvae were incubated and emerging adults were captured and identified. The overall prevalence of CCM was 45% (180/400) (95% confidence interval: 40.0–50.0%). A total of 434 larvae were collected from 180 dogs infested with cutaneous myiasis. All larvae (100%) were identified as C. anthropophaga and hatched adults were “tumbu” flies. There were no significant differences in the prevalence of CCM at 95% confidence interval among different age and sex groups (p > 0.05), although puppies (<6 months) appeared more affected. The highest prevalence of myiasis was in Kitui Central at 65% (95% confidence interval: 51.6–76.9%), Mwingi North at 52.5% (95% confidence interval: 36.1–68.4%), Kitui South at 48.5% (95% confidence interval: 31.5–63.9%), Kitui Rural at 40% (95% confidence interval: 27.6–53.5%), Mwingi Central at 40% (95% confidence interval: 24.9–56.7%), Mwingi West at 40% (95% confidence interval: 24.9–56.7%), Kitui West at 38.3% (95% confidence interval: 26.1–51.8%), and Kitui East subcounty at 36.7% (95% confidence interval: 24.6–50.1%). Lack of housing, housing structures, and dog living area environmental hygiene were the main risk factors associated with the occurrence of CCM (p < 0.05). The CCM occurrence was significantly different among breeds (p < 0.05). Cordylobia anthropophaga larvae were the etiological agent of CCM in Kitui County. There is a need for improved dog housing and hygiene measures to prevent the occurrence of CCM, and affected dogs should be treated to prevent the spread of CCM among the dogs.

Point-of-care ultrasound utilized for foreign body in a toe: A case report of botfly larvae

BackgroundMyiasis, as defined by the Centers for Disease Control and Prevention, is infection with fly larvae commonly occurring in tropical and subtropical areas. Whereas the presentation of skin infection with organisms such as Dermatobia hominis (human botfly) is more easily recognized in these regions, identification of myiasis in the United States is difficult due to its rarity. Due to unspecific signs and symptoms, myiasis may initially be mistaken for other conditions, like cellulitis. Case ReportThis case details a patient with pain, swelling, drainage, and erythema of the right second toe. The patient recently returned from Belize and reported an insect bite to the area approximately 1 month prior. She had been seen by health care professionals twice prior to presenting to our Emergency Department (ED) due to increasing pain. At those visits, the patient was prescribed antibiotics, failing to improve her symptoms. In the ED, point-of-care ultrasound (POCUS) of the soft tissue was performed and showed evidence of a foreign body consistent with cutaneous myiasis. Given the patient's history of travel to Belize and known insect bite, it is prudent to have an increased suspicion for cutaneous myiasis. Why Should an Emergency Physician Be Aware of This?To prevent a delay in diagnosis and unnecessary antibiotics, clinicians should have a high level of suspicion for botfly if a patient reports recent travel in an endemic region and pain disproportionate to an insect bite. POCUS contributes to a more efficient recognition of the disease.

Botfly Parasitism on Two Primates of the Cebidae Family in Peru.

Botflies (Diptera:Oestridae) are a diverse group of insect parasites that affect various vertebrate species. There are previous reports of myiasis affecting wild primates in Central and South America; however, information about botfly parasitism in Peruvian primates is scarce. We present data from two Cebidae primate specimens: a rescued large-headed capuchin monkey (Sapajus macrocephalus) housed at Taricaya Rescue Center, in Tambopata, Peru, and a free-ranging white-fronted capuchin monkey (Cebus albifrons aequatorialis) inhabiting Cerros de Amotape National Park. The first specimen had a larva identified as Dermatobia hominis, whereas Cuterebra baeri larvae infested the second. In both cases we initially identified the parasite species through their morphologic features before confirming the identification with genetic analysis through the cytochrome C oxidase subunit 1 mitochondrial gene sequencing of the larvae. Further field studies on the primate-parasite dynamics are needed to understand the impact of botfly myiasis on primate populations.

Myiasis by &lt;em&gt;Dermatobia hominis&lt;/em&gt; larvae in a post-menopausal patient having ulcerative vulvar carcinoma

68 years old, post-menopausal, multiparous, female having carcinoma of vulva extending up to urethra. She was having foul smelling blood stained discharge with poor personal hygiene was referred from a primary health centre. On examination there was large necrotic cauliflower like growth at labia majora and large number of larva of Dermatobia hominis were crawling in necrotic tissue.Larvae were removed followed by cleansing of the affected area and a course of antibiotics was given. Patient was referred to Oncology Deptt. for further management of vulvar malignancy.

Effectiveness of sarolaner in the clinical management of furuncular myiasis in dogs naturally infested with Dermatobia hominis (Diptera: Cuterebridae)

BackgroundThe human botfly, Dermatobia hominis, is a common cause of furuncular myiasis in dogs in Latin America. Lesions can be single or multiple, each harboring an individual larva, presented as an erythematous nodule that causes pruritus and pain. Typical treatment consists of sedation for removal of larvae by surgical incision or manual pressure. Medications to kill the larva before its extraction can reduce inflammation and discomfort and provide a less traumatic larval removal. Isoxazolines are broad-spectrum ectoparasiticides with larvicidal activity previously reported in the treatment of screwworm myiasis in companion animals. The aim of this study was to evaluate the effectiveness of sarolaner as part of the clinical management of furuncular myiasis in dogs caused by D. hominis larvae.MethodsTen short-haired mixed breed dogs naturally infested with D. hominis were enrolled. Clinical diagnosis was achieved by observation of skin nodules and visualization of larval motility through the lesion orifice. Sarolaner was administered at manufacturer recommended dose for fleas and ticks. Lesions were reexamined 24 h post-treatment and assessed for viability of larvae. Larvae were removed by digital compression and identified as D. hominis.ResultsSeventy-five D. hominis larvae were retrieved from ten dogs. No live larvae were observed, demonstrating 100% larvicidal efficacy of sarolaner. Skin lesions were healed 30 days post-treatment and new lesions were not observed.ConclusionsSarolaner seems to be effective as larvicidal treatment for dogs with furuncular myiasis, reducing discomfort caused by the presence of the larva in the skin and facilitating its safe removal.Graphical abstract

Furuncular myiasis caused by Dermatobia hominis in five cats and efficacy of topical fluralaner for its treatment.

Dermatobia hominis (D.hominis) is a botfly that causes furuncular myiasis in several species of domestic and wild animals. However, reports of feline infestation by larvae of this dipteran are rare. To report the natural occurrence of furuncular myiasis caused by D.hominis in five cats and the efficacy of topical fluralaner for its treatment. Five adult mixed-breed cats (four males, one female) were diagnosed and treated, all living in the state of Rio de Janeiro, Brazil. The cats were treated with topical fluralaner. After this treatment, the larvae were dead after 24h in three cats and after 48h in two. There was spontaneous expulsion of larvae in two cats, and it was necessary to perform manual expression for removal of dead larvae in the other three cats. Dermatobia hominis can cause furuncular myiasis in cats, although this appears to be less common than in other animal species. Topical fluralaner proved to be effective in the treatment of this parasitic disease.

Furuncular Myiasis by Dermatobia hominis (Diptera: Oestridae) in Wild Jaguars in the Amazon Rainforest.

Two individuals of the jaguar, Panthera onca (L.), were captured near the municipality of Presidente Figueiredo, Brazilian Amazon, during the years of 2017 and 2018. The jaguars presented furuncular myiasis caused by the human botfly Dermatobia hominis (L.) on the rear thighs and tail. This is the first record of infestation of D. hominis in P. onca in the Amazon region.

An Unusual Cause of Facial swelling – Bot Fly Larva in an Infant – A Case Report

‘Myiasis’ is a term used to describe an infestation of humans or animals with dipterous larvae [1]. Due to increased international travel in recent times, health professionals in the UK may encounter these infections more commonly than before. We present a case of a 6 month infant who had been bitten by Dermatobia hominis Bot fly in Brazil and travelled back to the UK. The original diagnosis was of an infected insect bite, which ultimately delayed appropriate management. A detailed travel history is therefore paramount and these types of infections should be considered in differential diagnoses. Management should also involve the infectious diseases team.